How is the polarization of an em wave change when propagating through fog or rain? Say the wave is initially vertically polarized, how will rain and fog change its polarization?
The polarization of an electromagnetic wave can be affected by rain and fog. Raindrops and fog droplets act as small dipoles, which means that they have a positive and negative charge. When an electromagnetic wave passes through rain or fog, the dipoles in the droplets interact with the wave and cause the wave's polarization to be changed.
The amount of change in polarization depends on the wavelength of the wave, the size of the droplets, and the density of the rain or fog. For shorter wavelengths, such as visible light, the change in polarization is more significant. For longer wavelengths, such as radio waves, the change in polarization is less significant.
The direction of the change in polarization depends on the orientation of the dipoles in the droplets. If the dipoles are randomly oriented, then the polarization of the wave will be randomly scattered. However, if the dipoles are aligned in a particular direction, then the polarization of the wave will be aligned in that direction.
For example, if a vertically polarized wave passes through rain or fog, the droplets will tend to rotate the wave's polarization to a horizontal direction. This is because the dipoles in the droplets are aligned horizontally, and they interact with the wave's electric field in a way that rotates the polarization.
The effect of rain and fog on polarization can be used to our advantage. For example, it can be used to improve the reception of radio waves. Radio waves are typically polarized horizontally, so if they pass through rain or fog, the polarization will be rotated to a vertical direction. This can be used to improve the reception of radio waves by using a vertical antenna.
The effect of rain and fog on polarization can also be used to study the properties of rain and fog. For example, by measuring the amount of change in polarization, we can learn about the size and density of the droplets. This information can be used to improve our understanding of rain and fog formation and behavior.